狂犬病是一种古老的人兽共患传染病,给人类生命造成严重威胁.2022 年广西钦州市钦南区出现多起犬伤人事件,有 1 例人狂犬病致死事件.为查明疫情起因,摸清疫情基本情况,开展了动物狂犬病紧急流行病学调查.调查结果显示,2022 年 3 月至 2023 年 2 月,钦南区共报告 11 起犬伤人事件,其咬伤 21 人,初步判断其中 8 例为犬狂犬病疑似病例,确诊 2 例.通过流行病学数据推测,钦南区及周边县区的乡村犬只存在携带狂犬病病毒现象,主要通过带毒的流浪犬咬伤健康家犬所致.由于钦南区犬只密度较高,犬免疫率和拴养率低,疫情扩散风险较大.本次疫情提示,加强犬只管理和提高犬只免疫密度是控制狂犬病的关键措施.应建立健全人和犬的狂犬病监测系统,采取综合防控措施,逐步在全区消除犬传人狂犬病.

为了解广西部分地区(玉林市、大新县、那坡县、东兴市、靖西市和百色市)猪群中猪链球菌(Streptococcus suis,SS)毒力基因的流行情况和毒力水平,试验采用PCR方法检测分离到的201株(经鉴定猪链球菌2&1/2型24株,猪链球菌7型2株,猪链球菌9型15株,一共41株)猪链球菌的毒力基因orf2、sly、ef和mrp,并通过斑马鱼模型筛选毒力较强的菌株,测定菌株的半数致死剂量(LD50).结果表明:从广西部分地区分离的201株猪链球菌的4种毒力基因携带率从高到低依次为orf2(85.6％,172/201)＞sly(55.2％,111/201)＞ef(33.8％,68/201)＞mrp(26.4％,53/201);6 个市县主要流行的毒力基因不同,玉林市、大新县、那坡县、东兴市、靖西市和百色市分离的猪链球菌携带最多的毒力基因分别为 orf2(100％)、orf2(89.2％)、orf2(91.5％)、ef(44.4％)、orf2(86.7％)、orf2(40.0％);经鉴定分型的41株猪链球菌中,有7株(17.1％,7/41)同时携带了 4种毒力基因,有11株(26.8％,11/41)同时携带了 3种毒力基因,有17株(41.5％,17/41)同时携带了 2种毒力基因;斑马鱼模型筛选出7株致病力较强猪链球菌,LD50 为4.2×107～3.8×108 cfu/mL,且猪链球菌2型菌株毒力和猪链球菌9型菌株毒力差别不大.说明广西部分地区分离的猪链球菌毒力基因携带率较高,各地区流行的毒力基因多样,对斑马鱼有明显的致病性,但毒力不强,未来应当更加关注猪链球菌9型的流行情况和毒力水平.

为探究广西部分地区猪群中猪链球菌(Streptococcus suis)的流行情况及耐药性,采集广西6个市县共527份猪组织及鼻腔拭子样品,通过选择培养基对样品中的猪链球菌进行分离和PCR鉴定,共分离到猪链球菌201株(38.1％).其中大新县和那坡县猪链球菌分离率最高,分别为64.0％(64/100)和65.4％(70/107),而靖西市截获的越南走私猪中猪链球菌分离率达29.3％(44/150).对分离到的猪链球菌进行血清型分型鉴定,结果显示201株猪链球菌血清型中2(1/2)型24株(11.9％),7型2株(1.0％),9型15株(7.5％),大新县、那坡县和东兴市主要流行2(1/2)型,靖西市的越南走私猪样品主要流行9型.采用纸片扩散法,测定41株广西猪链球菌分离菌株对临床上常见的34种9类抗生素的耐药性,其中有1株猪链球菌只对2类抗生素中度敏感,对7类抗生素不敏感;有12株(29.3％)细菌多重耐药;大多数猪链球菌(65.9％)对大环内酯类不敏感,对万古霉素(87.8％)、硝基呋喃(87.8％)、氟喹诺酮类(82.9％)敏感.由此可见广西地区猪链球菌分离株有较强的耐药性.

为了解广西壮族自治区犬传人狂犬病的防控形势,使用由FAO、GARC、WHO等共同开发的分阶段消除狂犬病(stepwise approach to rabies elimination,SARE)工具,从狂犬病信息教育传播、犬只管理、预防控制、数据收集分析、实验室诊断、跨部门事务和立法等7大类115个常规和技术问题,对广西狂犬病消除工作状况进行评估,并根据在狂犬病消除六阶段路线图(阶段0～5)中所处位置,来确定广西狂犬病消除进展阶段.结果显示:广西狂犬病消除进度处于阶段1.5;7大类活动的完成率为8.33％～91.67％,完成了 52项活动,还有86个待处理活动,其中待处理活动集中于犬只管理、多部门合作、信息宣传教育和预防控制等4个部分.结果表明:广西已具有消除犬传人狂犬病的良好基础,可以采取以犬只免疫为主,加强犬只管理、多部门合作、宣传教育和预防控制为辅的综合策略,逐步实现消除犬传人狂犬病的目标.

为了评价口蹄疫(FMD)O型、A型二价3B表位缺失灭活疫苗在奶水牛临床应用的安全性及免疫效果,本试验选择90～100日龄健康奶水牛犊牛24头,平均分为2个组,试验组接种表位缺失疫苗,在首免后30 d,二免后180 d加强免疫,对照组按照相同的免疫程序接种常规疫苗;在不同时间点采集血清进行口蹄疫O型、A型抗体效价和非结构蛋白3ABC抗体检测,采集食道-咽分泌液(OP)进行口蹄疫病原学检测.结果显示:在抗体平均滴度方面,试验组抗体比对照组高1.4～2.8个滴度,在9个免疫后时间点试验组O型抗体平均滴度全部显著(P＜0.05)甚至极显著(P＜0.01)高于对照组,7个免疫后时间点试验组A型抗体平均滴度显著(P＜0.05)甚至极显著(P＜0.01)高于对照组;试验组抗体合格率比对照组高出25％～41％;口蹄疫非结构蛋白3ABC抗体标记疫苗免疫动物均为阴性.综合分析表明,口蹄疫O型、A型二价3B表位缺失灭活疫苗具有良好的免疫保护效果,在感染抗体水平上也能保证非结构蛋白抗体阴性.本试验为口蹄疫净化和口蹄疫无疫小区、无疫区建设探索可行的方法.

2020年11月,广西河池市发生1起流浪犬咬伤人和牛事件,通过现场流行病学调查和实验室检测等判定为一起狂犬病疫情.将伤者送医并接受暴露后处置,同时对疫点的受伤牛、污染场地和其他犬只进行紧急处置.后续跟踪调查发现,伤者伤口已愈合,受伤牛发病后被扑杀且无害化处理;该地区犬和其他动物没有发现异常,也无狂犬病继发病例报告.本次突发公共卫生事件处置及时、诊断准确、防控措施有效,为该地区狂犬病防控工作提供参考.

2021年6月,广西某县一羊场检出布鲁氏菌阳性,怀疑当地暴发了羊布鲁氏菌病疫情.为确定病因,控制疫情,减少损失,防止类似事件再次发生,采用现场访谈、实地调查、问卷调查、采样检测等方式开展了流行病学调查.调查发现:此次疫情涉及该县2个乡镇3个行政村10个养殖场户;这10个阳性场户间有流行病学关联,存在混牧、公羊共用和销售调运羊只等情况.调查认为,违规引种而引进感染动物,不按规定对调入动物实施隔离饲养,养殖户生物安全意识差,是本次布鲁氏菌病疫情发生的主要原因.本次疫情警示,相关防疫部门应加强防疫知识及相关法规的宣传教育,提高养殖场户的生物安全意识和依法落实防疫主体责任意识,加强隔离饲养,避免混牧和公羊共用,依法规范引种、调运动物等行为.

本项目属于农牧渔业领域家禽疫病防控范畴,主要涉及高致病性禽流感、新城疫、禽白血病和鸡白痢4种重要疫病的防控与净化.本项目创新建立和应用种鸡场重要病原及耐药基因快速检测方法和以"免疫+监测+检测+风险评估"为核心的广西动物防疫信息化平台;创新构建和应用种鸡场生物安全体系;创新建立"监测流调+疫苗免疫+风险评估"综合防控模式并成功防控广西禽流感;创新建立和应用"生物安全+疫苗免疫+抗体/病原监测+补免/淘汰"防控模式净化种鸡场高致病性禽流感和新城疫及"生物安全+病原/抗体监测+淘汰"防控模式净化种鸡场禽白血病和鸡白痢;创新研发中药抗菌素复合组方和中药处方并应用于防治种鸡场重要细菌病.经济、社会、生态效益极为显著.

Most Chinese provinces have a daily-updated database of live animal movements; however, the data are not efficiently utilized to support interventions to control H7N9 and other avian influenzas. Based on official records, this study assessed the spatio-temporal patterns of live broilers moved out of and within Guangxi in 2017. The yearly and monthly networks were analyzed for inter- and intra-provincial movements, respectively. Approximately 200,000 movements occurred in 2017, involving the transport of 200 million live broilers from Guangxi. Although Guangxi exported to 24 out of 32 provinces of China, 95% of inter-provincial movements occurred with three bordering provinces. Within Guangxi, counties were highly connected through the live broiler movements, creating conditions for rapid virus spreading throughout the province. Interestingly, a peak in movements during the Chinese Lunar New Year celebrations, late January in 2017, was not observed in this study, likely due to H7N9-related control measures constraining live bird trading. Both intra- and inter-provincial movements in March 2017 were significantly higher than in other months of that year, suggesting that dramatic price changes may influence the movement's network and reshape the risk pathways. However, despite these variations, the same small proportion of counties (less than 20%) exporting/importing more than 90% of inter- and intra-provincial movements remains the same throughout the year. Interventions, particularly surveillance and improving biosecurity, targeted to those counties are thus likely to be more effective for avian influenza risk mitigation than implemented indiscriminately. Additionally, simulations further demonstrated that targeting counties according to their degree or betweenness in the movement network would be the most efficient way to limit disease transmission via broiler movements. The study findings provide evidence to support the design of risk-based control interventions for H7N9 and all other avian influenza viruses in broiler value chains in Guangxi.

为筛选可靠的牛结节性皮肤病免疫抗体评价方法,以已知牛结节性皮肤病感染牛血清17份、羊痘疫苗免疫牛/羊血清77份和阴性牛血清20份作为样品盘,以病毒中和试验结果作为金标准,通过Kappa一致性和诊断效能评价,分别对市售的4种牛结节性皮肤病/羊痘抗体ELISA检测试剂盒进行分析比对.结果显示:4种ELISA检测试剂盒特异性为87.5％～94.34％,敏感性均不足80％,其中2种试剂盒与病毒中和试验的符合率超过80％,一致性为高度.结果表明,在临床应用中应根据检测目的选用可靠的试剂盒.本研究为科学有效防控牛结节性皮肤病提供了技术支持.

In response to a sudden increase in H7N9 human infections, China introduced an H5/H7 bivalent inactivated vaccine for poultry in Guangxi and Guangdong provinces in July 2017, which subsequently became integrated into the existing compulsory national H5N1 vaccination programme from September 2017. Although the vaccination programme effectively reduced H7N9 infections in humans and poultry, there are ongoing arguments against continuing this long-term vaccination. These discussions have drawn policymakers to think about the possibility of stopping routine vaccination for H7N9 avian influenza viruses (AIVs) in China; however, they have not considered the poultry industry stakeholders' practices on and attitudes towards this vaccination. This study investigated H7N9 vaccination practices in the yellow broiler industry in Guangxi and stakeholders' attitudes on H7N9 vaccination, using a mixed methods design. The study found H7N9 vaccination was well adopted in the yellow broiler industry in Guangxi regardless of the source of the vaccines. Most stakeholders believed vaccination was the best measure to control H7N9 and H5N1 AIVs, and they showed a strong willingness to continue with vaccination even without government subsidies or freely provided vaccines. The motivations by stakeholders for using vaccines to control H7N9 and H5N1 were different due to the epidemiological differences between the two strains. Understanding poultry industry stakeholders' practices and attitudes on H7N9 vaccination has important practical implications in planning vaccination policies, particularly when considering the possibility of vaccination withdrawal.

Yellow broilers are the primary source of poultry consumption in China and the predominant trade of live poultry. However, knowledge of the value chain is limited, which is vital evidence for the effective control of H7N9 and other zoonotic avian influenzas. The aim of the study was to map the yellow broiler value chain in Guangxi Zhuang Autonomous Region, China and investigate its governance structure and practices relevant to the risk of H7N9 transmission. A value chain analysis was conducted in five areas of Guangxi from May to August 2018. To map the value chain, three focus group discussions (FGDs) were conducted and stakeholders, products and premises involved and their interactions were identified. Then, 55 key informant interviews (KIIs) collected qualitative data on stakeholders' profile, practices and interactions with other stakeholders and rules/norms that exist along the value chain. On-site observations were also carried out at different types of premises along the value chain to complement and validate findings of KIIs and FGDs. Participants were also asked to provide proportional estimates of each component in the value chain where possible. The qualitative data from FGDs, KIIs and on-site observations were analysed to create stakeholder profiles and a diagram of product flows and stakeholders' interactions. Thematic analysis was used to identify the governance structure of the value chains and practices relevant to the risk of H7N9 transmission. The stakeholders and premises involved in Guangxi yellow broiler production, wholesale and retail were described, as well as their interactions. Contract farming is extensively adopted in Guangxi; consequently yellow broiler grower companies are the dominant stakeholders. The trading platform was identified as a key premise linking farms and live bird markets. The thematic analysis highlighted poor biosecurity practices in different premises along the value chain, which was supported by on-site observations. The operation of trading platforms reported in this study presents a disease risk but is not considered in the current H7N9 control programs. The study suggested that biosecurity management gaps need to be addressed through government-industry partnerships that require engagement with private stakeholders in the planning and implementation of H7N9 control strategies incentivising participation of grower companies, wholesalers and retailers.

为评估广西边境地区高致病性禽流感防控形势,根据文献报道的高致病性禽流感风险评估模型,对生态环境、候鸟迁徙及数量、饲养模式、运输和贸易、屠宰和废物处理、本地和周边地区的疫情形势、预防和控制措施等7大准则层22项指标综合计算发现,边境县(市、区)高致病性禽流感发生风险概率>0.5,为中度风险以上,其中靖西、东兴、防城和港口发生风险概率>0.6,为高风险.高风险因素主要为:市场被污染、越南疫情严重、水禽占比高,饲养管理和生物安全水平低、位于候鸟迁徙线上、市场管理水平低、市场卫生条件差、屠宰管理不到位、边境地区兽医机构效能不高.为防止广西边境地区高致病性禽流感的发生,必须要提高生物安全措施、做好免疫接种、加强监测和流行病学调查工作、提高兽医机构效能.

新城疫病毒(NDV)是我国活禽最重要的疫病之一.2015-2017年对广西东兴市某活禽市场进行了系统监测,共采集到各种棉拭子样品1482份,将处理好的样品接种鸡胚,后运用荧光RT-PCR检测方法对待测样品进行检测和分析.结果显示,2015-2017年东兴市某活禽市场的NDV整体阳性率为2.43％,其中2015年阳性率最高为6.06％,2016年为0.74％和2017年为0.83％;NDV可以在鸡、鸭和环境样品中检测到,其中环境样品的阳性率最高为5.85％,鸡次之为2.78％,鸭最低为1.33％.NDV的流行病学调查和后续监测可为NDV的防治提供重要的流行病学信息.

为建立一种灵敏、可快速检测猪圆环病毒4型(PCV4)的SYBR Green I实时荧光定量PCR方法,根据PCV4 Rep基因的保守区域设计引物,建立针对PCV4的SYBR Green I实时荧光定量PCR检测方法,并对该方法的特异性、灵敏性和重复性进行评价.结果 显示,该检测方法的Ct值与标准品在5.64×102～5.64×109 copies/μL范围内呈良好的线性关系,R2为0.999,斜率为-3.638,检测下限为5.64×102 copies/μL,且无非特异性扩增.利用该方法对56份临床样品进行检测,发现PCV4核酸阳性率为3.57％,比普通PCR更灵敏可靠.结果 表明,本试验建立的SYBR Green I实时荧光定量PCR方法可用于PCV4的快速诊断.

为了解广西动物防疫物资管理情况,广西动物疫病预防控制中心采用现况调查法,制定调查表,对所辖市、县、乡三级动物疫病预防控制机构进行问卷调查.结果显示:100％的市级机构配备了动物疫苗冷藏设备,使用率达到92.86％,动物疫苗冷链运输温度100％合格,而县级机构的冷藏设备配备和使用率分别为75.23％和59.63％,仅67.89％能保障冷链运输温度;100％的市级、90.83％的县级、89.90％的乡级机构能够按要求贮存消毒药品,92％以上的各级机构能够按要求正确填写有关物资凭证,95％以上的各级机构能够做到"账账相符、账实相符";不到70％的乡级防疫机构回收屠宰、养殖环节的畜禽标识,不到70％的养殖场申报政府采购疫苗计划及对自购强制免疫疫苗进行备案.结果表明:广西市级机构的动物疫苗冷藏和冷链运输设备齐全,而县、乡两级配备明显不足;各级机构能够按要求贮存消毒药品,相关台帐、凭证管理到位,但畜禽标识回收率偏低,养殖场自购强制免疫疫苗备案意识淡薄.结果提示:应积极与财政部门沟通、协调,争取资金,完善基层机构的动物疫苗冷藏设施设备配备;加强各环节畜禽标识的回收和销毁管理,尽快建立"移动戴标制度";继续加强物资监管,做好重大动物疫病防控应急物资的储备和管理工作.

高致病性猪蓝耳病(HP-PRRS)是当前严重危害养猪业的一类动物传染病,做好该病的防控意义重大.该成果成功建立了6种PRRSV美洲型经典株、变异株及欧洲型毒株的快速鉴别检测方法,并应用于临床样品的检测和诊断;制定了HP-PRRS、猪瘟、口蹄疫3种疫苗的"321法"和"332法"免疫程序,并在临床大面积推广应用;明确了当前广西PRRSV流行毒株的基因型、优势基因亚群及其遗传变异新特点,并用以指导广西选择疫苗种类和毒株;明确了HP-PRRSV流行毒株在疫苗免疫猪场比非免疫猪场的进化速率要快,并用以指导猪场制定合理的免疫策略;证实野毒感染和母源抗体不影响HP-PRRS弱毒疫苗的免疫效果,并应用于临床监测和防控效果评估.获得2件国家发明专利,制定4项地方标准,发表核心期刊论文22篇,完成硕士论文5篇,获奖论文14篇.培养6名研究生、培训基层防疫人员2.4万人次.该成果在广西推广应用,2015-2017年产生经济效益35,558.72万元,经济、社会和生态效益极为显著.

为了丰富禽流感病毒(AIV)神经氨酸酶(NA)的分子流行病学资料,通过对2016年在广西活禽市场分离的4株鸭源H6N2亚型AIV的NA基因进行分析,发现其NA基因全长约1449bp,开放阅读框(ORF)位于第19～1428位,长度均为1410bp,ORF编码469个氨基酸.将广西4个毒株的NA基因与广东、湖北、华东地区等共14个H6 N2毒株的NA基因进行比较,并绘制了基因遗传进化树.结果显示:广西的4株H6 N2亚型分离株的NA基因之间的核苷酸相似性为99.7％～99.9％;而与其他14个毒株的相似性在93.5％ ～99.6％之间,与2009年广东分离株的相似性最高为99.6％、2008年湖北毒株分离株相似性次之为98.5％、2008年华东分离株的相似性最低为93.5％.表明H6N2亚型AIV流行毒株的NA基因亲缘关系与空间距离密切相关,在一定的时间内距离越近相似性越高,同时,亲缘关系随着毒株分离的时间变化而变化,年代相距越远,亲缘关系越低.

为了解中越边境地区H9亚型禽流感病毒(AIV)的流行情况,本研究收集2012年12月～2015年12月广西边境地区主要活禽市场和养殖场的家禽拭子及环境样品,采用病原分离和鉴定方法对样品进行了分析.结果显示,H9亚型AIV整体分离率为3.01％,其中冬春季节(3.47％)高于夏秋两季(1.39％);市场样品的病毒分离率(3.73％)高于养殖场(1.53％);在鸡、鸭、鹅源样品中均能检测到H9亚型AIV,其中鸡源样品的H9亚型AIV分离率最高(7.68％),鹅次之(1.43％).本研究表明,H9亚型AIV在广西边境地区表现出一定的时间、空间和群间分布特征.本研究对H9亚型AIV进行跟踪监测可为预防和控制禽流感提供重要的流行病学信息.